Autonomic Nervous System Dysfunction in Stroke Patients: Clinical Asessment by Sympathetic Skin Response(SSR) and Heart Rate Variability.

Cardiovascular complications included arrhythmias and sweating dysfunction are frequently encountered manifesting of autonomic failure in stroke patients. They are commonly associated with impaired activity of the autonomic nervous system. SSR (Sympathetic Skin Response) is an electrophysiological technique for assessing sympathetic function by monitoring a change in skin potential. SSRs are easily elicited by magnetic stimulation of the neck. The suppression of SSRs, which may be caused by disturbance of the sympathetic sudomotor pathway, were observed in stroke patients. Power spectral analysis of heart rate variability from electrocardiographic recording provides a useful method for evaluating quantitative both sympathetic and parasympathetic autonomic effects on the heart. The components of heart rate variability, especially high frequency component were reduced, and the circadian fluctuation of heart rate variability was observed in stroke patients. Cerebrovascular disease seems to cause the damage to the cardiovascular autonomic regulatory system. SSR and heart rate variability are useful and noninvasive methods for evaluating the autonomic nerve function in stroke patients.